For Taiwanese food don’t bother trying to make them yourself. You wont save money and some of them are sufficiently hard to make that it isn’t even worth it to try.
But for western food it would make better sense to make it at home. Except the ingredients are expensive. Especially cheese.
Yea majority of online retailers take payment this way. Because paypal will not accept domestic payments and it is very hard for small businesses to accept credit cards, which is why so few places accept them. It’s not like in the states where you can just go around without cash because everyone, even food stands and farmers market can accept cards by using this weird device that plugs into smartphones.